1.Field of the Invention
The present invention relates to a double-deck elevator car whereby the raising and lowering of a cage frame comprising two vertically arranged cage chambers is controlled.
2. Description of the Related Art
Double-deck elevator cars are often used as a vertical means of transport within ultra-high-rise buildings and elsewhere in order to improve the efficient use of space. Capable of carrying large volumes of traffic, double-deck elevator cars comprise two vertically arranged cage chambers. With ordinary double-deck elevator cars, the distance between the two cage chambers is fixed, so that the height of all stories must be uniform if the upper and lower cage chambers are to land simultaneously.
Meanwhile, with the object of allowing the upper and lower cage chambers to land simultaneously where the height of the stories in a building is not uniform, double-deck elevator cars have been developed as disclosed in Japanese Laid-Open Patent Applications S48[1973]-76242 and H10[1998]-279231, wherein the distance between the upper and lower cage chambers is variable.
FIG. 1 is an explanatory diagram illustrating the double-deck elevator car disclosed in Japanese Laid-Open Patent Application S48[1973]-76242, wherein the distance between the cage chambers is variable. As FIG. 1 shows, two cage chambers (an upper cage chamber 2 and a lower cage chamber 4) are fitted within the cage chamber 1 of the double-deck elevator car, and a cage chamber drive device is fitted to one of them (the lower cage chamber 4 in the case of FIG. 1). The cage chamber drive device comprises a guide roller 5 fitted to the cage frame 3 of the lower cage, and an actuator 6 which drives the guide roller 5. The lower cage chamber 4 is driven by the actuator 6 while being guided by the guide roller 4. In this manner it is possible to alter the distance between the upper and lower cage chambers.
Similarly, FIG. 2 is an explanatory diagram illustrating the double-deck elevator car disclosed in Japanese Laid-Open Patent Application H10[1998]-279231, wherein the distance between the cage chambers is variable. As FIG. 2 shows, a crank 7, motor 8 and ball screw 9 are employed as the cage chamber drive device, and the upper and lower cage chambers are made to move in opposite directions while keeping their weights balanced. This makes it possible to alter the distance between the upper and lower cage chambers without consuming too much power. In other words, the upper cage chamber 2 and lower cage chamber 4 are attached to the crank 7, which is itself attached to the centre of the cage frame 1, and two chambers are driven by the motor 8 and ball screw 9 in mutually opposite directions while retaining balance by virtue of their respective weights.
In this manner, a cage chamber drive device is attached to either the upper cage chamber 2 or the lower cage chamber 4, which allows the height of the cage chambers to be altered, thus making it possible to vary the distance between them.
FIG. 3 illustrates a characteristic conventional speed pattern where the movable cage chamber is allowed to land by operating the cage chamber drive device after the double-deck elevator car stops. The characteristic curve S1 represents the running speed pattern of the hoist which drives the cage frame 1 of the double-deck elevator car, while the characteristic curve S3 represents the running speed pattern applied to the movable cage chamber by the cage chamber drive device. In this case the hoist drives the whole cage frame 1 and stops, after which it allows the movable cage chamber to land by driving it until the floor height of each story is matched.
FIG. 4 illustrates a characteristic conventional speed pattern where the cage chamber drive device is operated during the running of a double-deck elevator car in order to allow a movable cage chamber to land at a floor. The characteristic curve S1 represents the running speed pattern of the hoist, while the characteristic curve S3 represents the running speed pattern applied to the movable cage chamber by the cage chamber drive device. The characteristic curve S2 represents the speed changes in the movable cage chamber. In this case the speed change S2 of the movable cage chamber is the sum of the running speed pattern S3 applied to the movable cage chamber by the cage chamber drive device and the running speed pattern S1 of the hoist. Thus, the speed change pattern S2 of the movable cage chamber changes in a less regular manner than the normal running speed pattern of an elevator car.
If the distance between the two cage chambers of a double-deck elevator car is adjusted by operating the cage chamber drive device after the cage frame has stopped, as in FIG. 3, running time is prolonged, which is inconvenient and uncomfortable for the passengers. It is also problematic because it leads to decreased transport capacity.
If on the other hand the cage chamber drive device is operated in such a manner that the distance between the two cage chambers is adjusted while the cage frame is running, as in FIG. 4, the problem is that it imparts a feeling of strangeness and anxiety to the passengers because the movement of the movable cage chamber is different from that of an ordinary cage frame 1.
Accordingly, one object of the present invention is to provide a novel double-deck elevator car wherein it is possible to adjust the vertical distance between the cage chambers during operation in such a manner that the passengers do not sense any anxiety or discomfort.
With a view to attaining the above object, the present invention is a double-deck elevator car equipped with hoist for raising and lowering a cage frame on which are mounted two vertically arranged cage chambers, a hoist control device which controls the hoist and the speed of the cage frame, a cage chamber drive device which drives at least one of the vertically arranged cage chambers so as to alter the relative distance between the two cage chambers, and a cage chamber position control device which controls the cage chamber drive device, characterised in that the hoist control device controls the hoist in such a manner as to maintain a constant speed once the speed change of the cage frame has accelerated at a set rate of acceleration, then to decelerate at a set rate of deceleration and stop, and the cage chamber position control device controls the cage chamber drive device in such a manner as to allow the speed change of the cage chamber driven by the cage chamber drive device after the addition of the speed change of the cage frame to accelerate at a set rate of acceleration, to maintain a constant speed, then to decelerate at a set rate of deceleration and stop.
In the double-deck elevator car to which the present invention pertains, the hoist is controlled in such a manner as to maintain a constant speed once the speed change of the cage frame has accelerated at a set rate of acceleration, then to decelerate at a set rate of deceleration and stop. Meanwhile, the cage chamber drive device is controlled in such a manner as to allow the speed change of the cage chamber driven by the cage chamber position control device after the addition of the speed change of the cage frame to accelerate at a set rate of acceleration, to maintain a constant speed, then to decelerate at a set rate of deceleration and stop.